Door latch

ABSTRACT

A door latch includes a reciprocating bolt having an elongated bolt opening therethrough. A pair of escutcheon plates close an opening through a door in which the bolt is mounted. The escutcheon plates have cooperating connecting means extending through the elongated bolt opening for connecting the two escutcheon plates together and to the door. The bolt reciprocates relative to the connecting means. A knob has an elongated shank extending through an elongated opening in one escutcheon plate. The shank is connected with the bolt.

United States Patent [1 1 Dielman Mar. 26, 1974 DOOR LATCH [75] Inventor: Harold J. Dielman, Lyndhurst, Ohio [21] Appl. N0.: 279,269

[52] US. Cl. 292/145, 292/357 Primary ExaminerAlbert G. Craig, Jr. Attorney, Agent, or FirmMeyer, Tilberry & Body [57] STRACT A door latch includes a reciprocating bolt having an elongated bolt opening therethrough. A pair of escutcheon plates close an opening through a door in which the bolt is mounted. The escutcheon plates have cooperating connecting means extending through the elongated bolt opening for connecting the two escutcheon plates together and to the door. The bolt reciprocates relative to the connecting means. A knob has an elongated shank extending through an elongated opening in one escutcheon plate. The shank is connected with the bolt.

11 Claims, 10 Drawing Figures [51] Int. Cl. E05c N04 [58] Field of Search 70/452; 292/74, 145-154, 292/357 [56] References Cited UNITED STATES PATENTS 3,650,555 3/1972 Mott et al. 292/145 3,l8l,904 5/1965 Fallarino et al.... 292/93 3,405,960 10/1968 Wargo 292/145 FOREIGN PATENTS OR APPLICATIONS 156,908 l/l92l Great Britain 292/175 62 43 c W M \mrllllll PAIENIEUmzs 1914 saw 1 BF 3 cab/9959s PMENTEDmzs 1914 SHEET 2 OF 3 PATENIEUIARZG 1914 saw 3 OF 3 DOOR LATCH BACKGROUND OF THE INVENTION This application relates to door latches and more particularly to door latches of the type having a reciprocating bolt. The invention is particularly applicable for use with doors and will be particularly described with reference thereto. However, it will be appreciated that the invention has broader applications and may be used for securing any movable closure in a locked position.

Partitions are commonly used in public places to form cubicles. Such cubicles commonly have doors with latches operable from the inside of the cubicle so that an occupant of the cubicle may have privacy. Examples of such cubicles include toilet partitions at airports, office buildings and other public places. Latches used on doors for such cubicles must be economical to manufacture and simple to install. At the same time, such latches must be simple in operation and be capable of taking considerable abuse.

SUMMARY OF THE INVENTION The present application relates to a door latch for use on a door having opposite faces and a vertical edge. A recess is formed in the door extending inwardly from the vertical edge intermediate the opposite faces. A bolt member is mounted in the recess for reciprocating movement in predetermined opposite directions substantially perpendicular to the vertical edge. The door has an opening therethrough spaced inwardly from the vertical edge in alignment with the bolt member. The opening forms holes in the opposite faces of the door. The bolt member has an elongated bolt member opening therethrough in alignment with the opening through the door. A pair of escutcheon plates are positioned against the opposite faces of the door to close the opening therethrough. The escutcheon plates have cooperating connecting means thereon extending through the elongated opening in the bolt member for securing the escutcheon plates together against the opposite faces of the door. The bolt member reciprocates relative tothe cooperating connecting means. One escutcheon plate has an elongated slot therein which is elongated in a direction parallel to the predetermined direction in which the bolt reciprocates. A knob member has an elongated shank receivable through the elongated slot in the one escutcheon plate. The elongated shank on the knob member extends through a hole in the bolt member. Manual reciprocation of the knob member also reciprocates the bolt member.

In accordance with a preferred arrangement, the two escutcheon plates have interior faces which face the door. The cooperating connecting means on the escutcheon plates includes an elongated pin attached to the interior face of one escutcheon plate and an elongated socket attached to the interior face of the other escutcheon plate. Friction retaining means is provided for retaining the pin in the socket to hold the escutcheon plates together. With this arrangement, there are no screws or the like externally accessible which would allow vandals to disassemble the latch.

In a preferred arrangement, the elongated slot in the one escutcheon plate has a longitudinal axis. The coopcrating connecting means on that escutcheon plate is intersected by the longitudinal axis of the elongated slot.

In accordance with one arrangement, the elongated bolt member opening is als enlarged in a direction perpendicular to the predetermined opposite directions in parallel to the opposite faces of the door. This enables use of the latch with a rotatable knob having a cam operator for reciprocating the bolt.

In accordance with another aspect of the device, synthetic plastic slide washers are positioned on the elongated shank of the knob member on opposite sides of the one escutcheon plate.

In accordance with another aspect of the invention, the bolt member has an outwardly rounded terminal end surface, which in the locked position fits into a recess of the structural member adjacent the vertical edge of the door and means limit the insertion of said terminal end surface into the recess a distance less than the radius of curvature of the end surface such that in the locked position vigorous shaking of the door cams the terminal end surface against the outer edge of the recess and will shift the bolt member to an unlocked position.

It is a principal object of the present invention to provide an improved door latch assembly.

It is a further object of the present invention to provide an improved door latch which is economical to manufacture and simple to assemble.

It is another object of the present invention to provide a door latch which is very reliable in operation.

It is an additional object of the present invention to provide a door latch which minimizes the danger of damage due to abuse by members of the public or vandals.

BRIEF DESCRIPTION OF THE DRAWING The invention may take part in certain parts and arrangements of parts, preferred embodiments of which will be described in detail and illustrated in the accom' panying drawing which forms a part hereof.

FIG. 1 is a front elevational view of a portion of a door having the improved latch of the present invention incorporated therein;

FIG. 2 is a cross-sectional plan view looking generally in the direction of arrows 22 of FIG. 1;

FIG. 3 is a plan view of a metal strip used to form a friction retainer;

FIG. 4 is an elevational view looking generally in the direction of arrows 4-4l of FIG. 3;

FIG. 5 is a cross-sectional plan view looking generally in the direction of arrows 5--5 of FIG. 1;

FIG. 6 is a perspective illustration of a bolt member used with the latch assembly of FIG. 1;

FIG. 7 is a top elevational view of a door panel;

FIG. 8 is a partial end elevational view looking generally in the directions of arrows 8-28 of FIG. 7 and with portions cut away for clarity of illustration;

FIG. 9 is a partial side elevational view of the door panel of FIG. 7 with portions cut away to illustrate the mounting of a door latch; and

FIG. 10 is a cross-sectional plan view looking generally in the direction of arrows 10-10 of FIG. 9.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to the drawings, wherein the showings are for purposes of illustrating a preferred embodiment of the invention only and not for purposes of limiting same, FlGS. I and 2 show a section of a door A having opposite faces and 12, and a vertical edge 14 extending perpendicular to opposite faces 10 and 12. In the arrangement shown, door A is of the type having synthetic plastics laminate facing sheets 16 and 18 bonded to the opposite faces of a flake board core panel 20. Vertical edge 14 also has a plastic laminate facing sheet 22 thereon.

In accordance with one arrangement, a recess 24 is formed in core of door A. Recess 24 is in the form of a cylindrical bore extending substantially perpendicular to vertical edge 14 intermediate opposite faces 10 and 12 of door A. An elongated cylindrical bolt member B is received for sliding reciprocating movement in recess 24. Bolt member B reciprocates in predetermined opposite directions indicated by arrows 26 of FIG. 2. Bolt member B reciprocates in a longitudinal direction substantially perpendicular to vertical edge 14.

In accordance with one arrangement, bolt member B may be formed of synthetic plastic material such as a polyamide. Bolt member B has a bore 30 formed in one end thereof for receiving a cylindrical shank 32 on one end of a steel bolt insert C. Main cylindrical portion 34 of bolt insert C has an outer diameter substantially identical to the outer diameter of bolt member B. A stepped shoulder 36 is defined between main portion 34 and shank portion 32 of bolt insert C. This shoulder 36 butts against end 38 of bolt B in which bolt 30 is formed Shank portion 32 of bolt insert C may be secured within bore 30 by a suitable adhesive, or by mechanical fastening such as a set screw or pin. Bolt insert C then reciprocates with bolt member B.

In a preferred arrangement, bolt member B has an elongated bolt member opening 40 formed therethrough intermediate its opposite end portions 38 and 42. Elongated bolt member opening 40 is elongated in the same direction 26 in which bolt member B reciprocates relative to cylindrical recess 24. Bolt member B further includes a cylindrical hole 44 therethrough spaced toward rear end portion 42 from elongated bolt member opening 40. Both elongated bolt member opening 40 and hole 44 have central axes extending parallel to one another and perpendicularly intersecting the longitudinal axis of bolt member B.

An opening D is formed through door A substantially perpendicular to cylindrical recess 24 and in alignment with elongated bolt member opening 40. Opening D defines holes 48 and 50 in opposite faces 10 and 12 of door A. Plastic laminate facing sheets 16 and 18 are cut away to a greater diameter as at 52 and 54 down to core 20 concentric with holes 48 and 50. In the arrangement shown and described with respect to FIGS. 1 and 2, opening D, holes 48 and 50, and recesses 52 and 54 are circular.

In accordance with a preferred arrangement, holes 48 and 50 are closed by a pair of metal circular escutcheon plates E and F. Each escutcheon plate E and F has a plane flat face 56 and 58. The peripheral edges of escutcheon plates E and F are smoothly turned inwardly to define a circumferential flange portion 60 and 62 extending substantially perpendicular to flat faces 56 and 58. Escutcheon plates E and F are dimensioned so that flanges 60 and 62 snuggly fit within recesses 52 and 54 in plastic laminate facing sheets 10 and 12, and flanges 60 and 62 butt against opposite faces of core 20.

In one arrangement, each escutcheon plate E and F has an interior face 64 and 66 facing opposite faces 10 and 12 of door A. Escutcheon plate E has a cylindrical metal socket member 70 welded to its interior face 64 as at 72. Socket member 70 has a cylindrical opening 74 therein. Escutcheon plate F has a cylindrical metal pin 76 welded to its interior face 66 as at 78.

Socket member 70 and pin member 76 define cooperating connecting means for connecting escutcheon plates E and F together and holding those escutcheon plates against the opposite faces of door A. A barbed friction-type of retainer may be used for retaining pin 76 within opening 74 of socket member 70. FIG. 3 shows a strip of metal 80 which is punched to have outwardly extending barbs 82 and inwardly barbs 84. Metal strip 80 is then bent into a U-shaped configuration to define a retaining member G as shown in FIG. 5. Retaining member G is in a substantially U-shaped configuration having flanges 86 resting against the outer edge of socket member 70. Outwardly extending barbs 82 bite into the internal wall of socket member 70, while inwardly extending barbs 84 bite into pin 76 for preventing removal of pin 76 from socket member 70.

With the arrangement described, it will be recognized that the connecting means defined by socket member 70 and pin 76 provides an arrangement for interconnecting escutcheon plates E and F with no exterior screw or the like visible or accessible on the exterior surfaces of the escutcheon plates. This prevents vandals or other mischievous persons from disassembling the latch. In addition, the latch member is extremely simple to assemble because a workman need simply apply pressure to both escutcheon plates E and F in order to force them toward one another for securely locking the escutcheon plates together in firm engagement with opposite surfaces of core 20.

In accordance with another aspect of the device, escutcheon plate E has an elongated slot 88 therein. Slot 88 is elongated so that its longitudinal axis extends in the same direction as arrows 26. The central longitudinal axis of elongated slot 88 also centrally intersects socket member 70.

When the escutcheon plates are assembled in their proper location, elongated slot 88 also has a transverse central axis extending parallel to the transverse axes of opening 40 and hole 44 and bolt member B and intersecting the longitudinal axis of bolt member B. A knob member H has a manually graspable knob 90 and an elongated cylindrical shank 92 extending therefrom. Elongated shank extends through elongated slot 88 in escutcheon plate E and through hole 44 in bolt member B. Slide washers 94 of synthetic plastic material, such as a polyamide, are positioned on shank 92 on opposite sides of escutcheon plate E. A metal locking washer 96 is positioned on shank 92 for holding interwasher 94 against axial movement on shank 92. Lock washer 96 may be of the known type having a central hole therethrough with circumferentially spaced radially extending barbs for biting shank 92. A pair of metal lock washers 102 like lock washer 96 are positioned on shank 92 on the opposite side of bolt member B from escutcheon plate E. Lock washers 102 securely hold shank 92 to bolt member B and prevent axial dislodgment of knob member H.

In order to assemble the described latch, bolt member B is first positioned in cylindrical recess 24. One

washer 94 is then placed on shank 92 of knob member H. Elongated shank 92 is then extended through elongated slot 88 in escutcheon plate E. Another slide washer 94 and lock washer 96 are then positioned on elongated shank 92. Friction retainer G is then positioned within socket member 70. Escutcheon plate E is then positioned within recess 52 so that socket member 70 extends through elongated bolt member 40, and elongated shank 92 extends through hole 44. Lock washers 102 are then positioned over shank 92 for holding shank 92 to bolt member B. Escutcheon plate F is then moved toward face 12 of door A so that pin 76 enters friction retainer G. Force is applied against escutcheon plates E and F until both plates are snuggly received against opposite faces of core 20. The latch is then ready for operation. In the position shown in FIG. 2, bolt member B is fully retracted and knob member H is at its extreme right position. Movement of knob member H to the left in FIG. 2 will slide bolt member B to the left so that bolt insert C will project outwardly from vertical edge 14 of door A and enter a recess 106 in an adjacent partition for holding door A in a closed and locked position. Door A is opened simply by again manually grasping knob 90 of knob member H and shifting bolt member B to the right in FIG. 2. Elongated bolt member opening 40 allows bolt member B to shift relative to the connecting means defined by socket member 70 and pin 76 on escutcheon plates E and F.

In accordance with another arrangement, the improved features of a door latch constructed in accordance with the present invention are incorporated in a door panel I as shown in FIG. 7. Door panel I includes opposite faces 110 and 112. Door I includes opposite metal facing sheets 116 and 118, and a core 120 of tibrous glass sheets or cellular paper board. The opposite longitudinal edges of metal facing sheets 116 and 118 are bent over the longitudinal edges of panel I and then diverge outwardly as at 121 and 122. Spot welding as at 123 firmly connects metal facing sheets 116 and 1118 together in firm engagement with core 120. Elongated arcuate members 124 having inturned flanges 125 are received over diverging end portions 121 and 123 at the opposite longitudinal edges of door I.

In a location at a desirable height for mounting a door latch, flanges 121 and 122 of facing sheets 116 and 118 are cut away at vertical edge 134 as shown in FIG. 8. A rectangular opening 135 is formed in edge 134 and a recess 136 is formed in core 120 for receiving a bolt mounting member J. Bolt mounting member J and its manner of attachment to door I is described in US. Pat. No. 2,876,873 to Benham and the disclosure of the Benham patent is hereby incorporated in this application by reference. Bolt mounting member I has vertically extending projections 137 which extend above and below rectangular opening 135 into the area where flanges 121 and 122 are cut-away. Projections 137 are received within arcuate members 124. Bolt mounting member J has upper and lower guideways 138 for reciprocatingly supporting bolt member K for longitudinal reciprocating movement in the direction of arrows 139 perpendicular to vertical edge 134 of door 1. Bolt member K is recessed for receiving leaf springs 140 which mount bolt member K in slide member J for easy reciprocating movement. Bolt member K may also be formed of synthetic plastic material such as a polyamide and has a bore 142 therein for receiving shank portion 144 of steel bolt insert 146. Shank portion 144 may be held within recess 142 by adhesive, or by a mechanical lock such as a set screw or pin. Bolt mounting member J has an opening 148 through which bolt insert 146 projects. Bolt member K has an elongated opening 150 therein which is elongated in the same direction as that in which bolt member K reciprocates. The connecting means defined by pin 76 and socket extends through elongated opening in the position generally shown by dotted lines for socket 70 in FIG. 9. This allows bolt member K to reciprocate freely relative to the defined connecting means. Bolt member K has a hole 152 therethrough for receiving shank 92 of knob H. Metal facing sheets 116 and 118 are deformed inwardly to define circular recesses and 162 having circumferential terminal flanges 164 and 166 extending parallel to opposite faces 110 and 112. Escutcheon plates E and F have the terminal edges of their flanges 60 and 62 bearing against flanges 164 and 166. Assembly of escutcheon plates E and F, and of knob member H is the same as described with respect to the assembly of FIGS. 1 and 2. Bolt member K reciprocates substantially perpendicular to edge 134 so that bolt insert may be selectively engaged and disengaged with respect to hole 176 on an adjacent panel or jam. In the arrangement shown and described, recesses 160 and 162 are preferably dimensioned so that outer faces 56 and 58 are substantially flush with outer faces 110 and 112 of door I. In the arrangement of FIGS. 9 and 10, elongated opening; 150 is also enlarged in a direction perpendicular to the reciprocating direction of bolt member K. This provides cam surfaces 178 and 180 as shown in FIG. 9 so that reciprocating knob H may be replaced with a rotatable door operator having a cam member mounted therein within opening 150 for cooperation with cam surfaces 178 and 180 to reciprocate bolt member K in response to rotation of the knob. Such an arrangement is shown and described in the aforementioned patent to Benham.

In the arrangement shown and described, the connecting means defined by socket member 70 and pin member 76 may be reversed if so desired so that socket member 70 would be on escutcheon plate E and pin member 76 on escutcheon plate F. In any event, socket member 70 and pin member 76 define first and second structures, and each of those structures is mounted to the interior face of one of the escutcheon plates.

In accordance with another aspect of the invention, particularly with respect to the embodiment of FIGS. 1 and 2, the bolt member is specifically formed and constructed so that a door can be opened from outside a compartment even though the bolt is in its locked position. As shown in FIGS. 1 and 2, bolt insert C forms one end portion of bolt member B. Bolt insert C is provided with a terminal end surface 202 which is outwardly curved to form somewhat of a bullet nose. Terminal end surface 202 may lie on the surface of a sphere having a radius substantially the same as the radius of cylindrical portion 34 of bolt insert C. Smoothly curved surface 202 intersects cylindrical surface 34 along a circumferential line as at 204. Recess 106 in latch member 206 on an adjacent panel or post 208 has a bottom 210. Recess 106 on latch member 206 also has an outer peripheral edge 212. Bolt member B is movable from the solid line unlocked position shown to the dotted line locking position. In the locking position, terminal end surface 202 strikes against the bottom 210 of recess 106. In effect, the end surface 206 enters recess 106 a distance at least less than its radius of curvature. In this position, intersecting circumferential line 204 between cylindrical portion 34 and curved terminal end surface 206 is still outwardly of outer edge 212 of recess 106. The frictional resistance of bolt member B against sliding inwardly in recess 24, along with the frictional resistance of knob member 90 sliding relative to escutcheon plate E, holds bolt member B in this extended and locked position. A single blow or shove on door A will not allow door A to open because terminal end surface 206 will remain within recess 106. In the event that a person becomes sick within the compartment or a small child locks himself in and does not know how to open the lock, door A may be opened from outside the compartment. Door A may simply be grasped at its upper or lower edge and vigorously shaken back and forth. This will cause outer edge 212 of recess 106 to act in somewhat of a cam fashion against curved terminal end surface 202 so that bolt B will be forced axially inward in recess 24 until terminal end surface 202 clears outer edge 212 of recess 106. Door A can then be opened. The vigorous shaking also causes bolt member B to vibrate relative to recess 24 so that the frictional resistance is overcome. Other shapes than those described may be used on terminal end surface 202. It is simply necessary that terminal end surface 202 be smoothly curved so that it will hold door A in a closed position during normal use,

and will allow some cam action when door A is vigorously vibrated. Smoothly curved terminal end portion 202 also helps to prevent damage to bolt member B or door A if bolt member B is extended to its locking position when door A is open. In such an occurrence, closing movement of door A would normally cause bolt insert C to strike sharply against latch member 206. This may rupture door A or break bolt member B. However, smoothly curved terminal end surface 202 will simply strike against an outer surface 214 on latch member 206 to cam bolt member inwardly so that damage is prevented.

' Although the invention has been described with reference to certain preferred embodiments, it is obvious that equivalent alterations and modifications will occur to others skilled in the art upon the reading and under standing of this specification. The present invention includes all such equivalent alterations and modifications and is limited only by the scope of the claims.

Having thus described my invention, 1 claim:

1. A reciprocating latch bolt assembly for a door having opposite faces and an edge surface, a recess formed in said door extending inward from said edge surface intermediate said opposite faces, a bolt member reciprocatingly positioned in said recess for reciprocating movement in predetermined opposite directions substantially perpendicular to said edge surface, an opening through said door, said opening being spaced inwardly from said edge surface and intersecting said recess, said opening defining holes in said opposite faces, a pair of escutcheon plates positioned against said opposite faces and closing said holes, one of said plates having an elongated opening therein elongated in said predetermined opposite directions, a knob member having an elongated shank slidably received through said elongated opening in said escutcheon plate for reciprocating movement in said predetermined opposite directions relative to said escutcheon plates, a hole in said bolt member, said elongated shank being received in said hole for connecting said knob member to said bolt member so that manual force applied to said knob in said predetermined opposite directions reciprocates said bolt member, an elongated bolt member opening in said bolt member elongated in said predetermined opposite directions and aligned with said opening through said door, and cooperating connecting means on said escutcheon plates extending through said elongated bolt member opening and connecting said escutcheon plates together, said bolt member being reciprocable relative to said connecting means.

2. The latch of claim 1 wherein said. escutcheon plates have interior surfaces facing said door, said cooperating connecting means comprising pin means attached to said interior surface of one of said escutcheon plates and socket means attached to said interior surface of the other of said escutcheon plates, said pin means being received in said socket means, and friction retainer means for securing said pin means in said socket means.

3. The latch of claim 2 wherein said elongated bolt member opening has a longitudinal axis extending parallel to said predetermined directions and said longitudinal axis intersects said hole in said bolt member.

4. The latch of claim 3 wherein said bolt member is substantially cylindrical.

5. The latch of claim 3 wherein said bolt member is substantially rectangular and said elongated bolt member opening is enlarged in a direction parallel to said opposite faces of said door and perpendicular to said predetermined opposite directions.

6. The latch of claim 1 wherein said escutcheon plates have interior surfaces facing said door, said cooperating connecting means comprising pin means attached to said interior surface of one of said escutcheon plates and socket means attached to said interior surface of the other of said escutcheon plates, said pin means being received in said socket means, and friction retainer means for securing said pin means in said socket means.

7. The latch of claim 1 wherein said escutcheon plates are in spaced relationship to said bolt member and said bolt member reciprocates relative to said escutcheon plates out of contact therewith.

8. The latch of claim 1 wherein said elongated opening in said one escutcheon plate has a longitudinal axis and said escutcheon plates have interior faces, said connecting means comprising a pin and a socket defining first and second connecting structures, one of said first and second structures being attached to each of said interior faces, said structure attached to said inter ior face of said one escutcheon plate being intersected by said longitudinal axis.

9. The latch of claim 1 and further including synthetic plastic slide washer means positioned on said elongated shank of said knob member on opposite sides of said one escutcheon plate.

10.. The latch of claim 1 wherein'said bolt member has an end portion adjacent said edge surface of said door for reception in a recess in a structural member adjacent said edge surface of said door, said bolt member being shiftable in one direction to move said end portion outwardly relative to said edge surface to a locking position received in said recess and in an opposite direction to move said end portion inwardly relative to said edge surface to an unlocked position out of said recess, said end portion having an outwardly rounded terminal end surface and said recess having an outer edge at least a portion of said terminal end surface being aligned with said outer edge of said recess in said locking position of said end portion of said bolt member, whereby vigorous shaking of said door impacts said terminal end surface against said outer edge of said recess for shifting said bolt member in said opposite direction to said unlocked position.

11. In a reciprocating unbiased latch bolt assembly for a door having an edge surface, a bolt member reciprocatingly mounted on said door for reciprocating movement in opposite directions substantially perpendicular to said edge surface, said bolt member having an end portion adjacent said edge surface of said door for reception in a recess in a structural member adjacent said edge surface of said door, said bolt member being shiftable in one direction to move said end portion outwardly relative to said edge surface to a locking position received in said recess and in an opposite direction to move said end portion inwardly relative to said edge surface to an unlocked position out of said recess, the improvement which comprises said end portion having an outwardly rounded terminal end surface and said recess having an outer edge, and means limiting insertion of said terminal end surface into said recess such that in the locking position at least a portion of said terminal end surface is aligned with said outer edge whereby vigorous shaking of said door cams said terminal end surface against said outer edge and shifts said bolt member to said unlocked position. 

1. A reciprocating latch bolt assembly for a door having opposite faces and an edge surface, a recess formed in said door extending inward from said edge surface intermediate said opposite faces, a bolt member reciprocatingly positioned in said recess for reciprocating movement in predetermined opposite directions substantially perpendicular to said edge surface, an opening through said door, said opening being spaced inwardly from said edge surface and intersecting said recess, said opening defining holes in said opposite faces, a pair of escutcheon plates positioned against said opposite faces and closing said holes, one of said plates having an elongated opening therein elongated in said predetermined opposite directions, a knob member having an elongated shank slidably received through said elongated opening in said escutcheon plate for reciprocating movement in said predetermined opposite directions relative to said escutcheon plates, a hole in said bolt member, said elongated shank being received in said hole for connecting said knob member to said bolt member so that manual force applied to said knob in said predetermined opposite directions reciprocates said bolt member, an elongated bolt member opening in said bolt member elongated in said predetermined opposite directions and aligned with said opening through said door, and cooperating connecting means on said escutcheon plates extending through said elongated bolt member opening and connecting said escutcheon plates together, said bolt member being reciprocable relative to said connecting means.
 2. The latch of claim 1 wherein said escutcheon plates have interior surfaces facing said door, said cooperating connecting means comprising pin means attached to said interior surface of one of said escutcheon plates and socket means attached to said interior surface of the other of said escutcheon plates, said pin means being received in said socket means, and friction retainer means for securing said pin means in said socket means.
 3. The latch of claim 2 wherein said elongated bolt member opening has a longitudinal axis extending parallel to said predetermined directions and said longitudinal axis intersects said hole in said bolt member.
 4. The latch of claim 3 wherein said bolt member is substantially cylindrical.
 5. The latch of claim 3 wherein said bolt member is substantially rectangular and said elongated bolt member opening is enlarged in a direction parallel to said opposite faces of said door and perpendicular to said predetermined opposite directions.
 6. The latch of claim 1 wherein said escutcheon plates have interior surfaces facing said door, said cooperating connecting means comprising pin means attached to said interior surface of one of said escutcheon plates and socket means attached to said interior surface of the other of said escutcheon plates, said pin means being received in said socket means, and friction retainer means for securing said pin means in said socket means.
 7. The latch of claim 1 wherein said escutcheon plates are in spaced relationship to said bolt member and said bolt member reciprocates relative to said escutcheon plates out of contact therewith.
 8. The latch of claim 1 wherein said elongated opening in said one escutcheon plate has a longitudinal axis and said escutcheon plates have interior faces, said connecting means comprising a pin and a socket defining first and second connecting structures, one of said first and second structures being attached to each of said interior faces, said structure attached to said interior face of said one escutcheon plate being intersected by said longitudinal axis.
 9. The latch of claim 1 and further including synthetic plastic slide washer means positioned on said elongated shank of said knob member on opposite sides of said one escutcheon plate.
 10. The latch of claim 1 wherein said bolt member has an end portion adjacent said edge surface of said door for reception in a recess in a structural member adjacent said edge surface of said door, said bolt member being shiftable in one direction to move said end portion outwardly relative to said edge surface to a locking position received in said recess and in an opposite direction to move said end portion inwardly relative to said edge surface to an unlocked position out of said recess, said end portion having an outwardly rounded terminal end surface and said recess having an outer edge at least a portion of said terminal end surface being aligned with said outer edge of said recess in said locking position of said end portion of said bolt member, whereby vigorous shaking of said door impacts said terminal end surface against said outer edge of said recess for shifting said bolt member in said opposite direction to said unlocked position.
 11. In a reciprocating unbiased latch bolt assembly for a door having an edge surface, a bolt member reciprocatingly mounted on said door for reciprocating movement in opposite directions substantially perpendicular to said edge surface, said bolt member having an end portion adjacent said edge surface of said door for reception in a recess in a structural member adjacent said edge surface of said door, said bolt member being shiftable in one direction to move said end portion outwardly relative to said edge surface to a locking position received in said recess and in an opposite direction to move said end portion inwardly relative to said edge surface to an unlocked position out of said recess, the improvement which comprises said end portion having an outwardly rounded terminal end surface and said recess having an outer edge, and means limiting insertion of said terminal end surface into said recess such that in the locking position at least a portion of said terminal end surface is aligned with said outer edge whereby vigorous shaking of said door cams said terminal end surface against said outer edge and shifts said bolt member to said unlocked position. 